As explained in http://bugs.php.net/bug.php?id=39992, proc_terminate() leaves children of the child process running. In my application, these children often have infinite loops, so I need a sure way to kill processes created with proc_open(). When I call proc_terminate(), the /bin/sh process is killed, but the child with the infinite loop is left running.

Until proc_terminate() gets fixed, I would not recommend using it. Instead, my solution is to:1) call proc_get_status() to get the parent pid (ppid) of the process I want to kill. 2) use ps to get all pids that have that ppid as their parent pid3) use posix_kill() to send the SIGKILL (9) signal to each of those child pids4) call proc_close() on process resource

<?php$descriptorspec = array(0 => array('pipe', 'r'), // stdin is a pipe that the child will read from1 => array('pipe', 'w'), // stdout is a pipe that the child will write to2 => array('pipe', 'w') // stderr is a pipe the child will write to);$process = proc_open('bad_program', $descriptorspec, $pipes);if(!is_resource($process)) { throw new Exception('bad_program could not be started.');}//pass some input to the programfwrite($pipes[0], $lots_of_data);//close stdin. By closing stdin, the program should exit//after it finishes processing the inputfclose($pipes[0]);

//do some other stuff ... the process will probably still be running//if we check on it right away

$status = proc_get_status($process);if($status['running'] == true) { //process ran too long, kill it //close all pipes that are still openfclose($pipes[1]); //stdoutfclose($pipes[2]); //stderr //get the parent pid of the process we want to kill$ppid = $status['pid'];//use ps to get all the children of this process, and kill them$pids = preg_split('/\s+/', `ps -o pid --no-heading --ppid $ppid`); foreach($pids as $pid) { if(is_numeric($pid)) { echo "Killing $pid\n";posix_kill($pid, 9); //9 is the SIGKILL signal} }